Fuel pump for gas engines



April 23, 1929. E. CANOOSE FUEL PUMP FOR GAS ENGINES- Filed July 21,1926 6 Sheets-Sheet 1 Hz; H

FIG. 1.

April 23, 1 29- J. E.A-OO$E FUEL. PUMP FOR GAS ENGINES Filed July 21.1926 6 Sheets-Sheet 2 iPa/Z.

A W A.

J anvemcoz April 23, 1929. 'J.E. cANoosE I 1,710,044

FUEL PUMP FOR GAS ENGINES Filed Jury 21, 1926 e Sheets-Sheet 5 Fla. 6:

llllll Iv 1 x gjhveutoz April 23, 1929.

Filed July 21, 1926 ma 1 49 l /2/ I20 1/8 L g //9- 1 P i 3 i i:

J. E. CANOOSE FUEL FUN? FOR GAS ENGINES 6 Sheets-Sheet 4 7 E anon/Wot.Apfi]Z3,19Z9 J.E@CANOOSE L Q FUEL PUMP FDR GAS ENGINES Fild July 21,1926 e Sheets$heet 5 Fm. l5

Apr il 23, 1929. J. E. CANOOSE FUEL PUMP FOR GAS ENGINES 6 Sheets-Sheet6 Filed July 21., 1926 5n. 7 a ml M nulh HIW m U FnZI.

Swuvntoz uNlTEDsr-A'Tes renn n. csiwoosn, or rmw Lonnon, comlmcrrc'u'r;I

i y f rum. rnntrronsas mamas i Ellipllcatton filed 11 11 21,

7 This invention relates to improvements in gas engines and moreparticularly to volume indicators withnecessary accessories for gasengines of the Diesel type or,of any type wherein a pump is used toforce oil-or other liquid fuel to the working cylinder or cylindersofthefengine. I

In order that a clearer-perception of the present invention may behadand of the object .s'oughtto be accomplished thereby, the volumeindicator withI its accessories 1 ill be hereinafter described withparticularurela; tion'to its application to Diesel enginesfor 5measuringwithoutjstopping the engine, the

amount of fuel beingfldelivered; to the various cylinders," thereby'Penabling the operator to determine easily and with extremeaccuracy theperformariceofthe fuel measuring pump without havin to resort to thetedious and usual method of? taking indicator cards, of the pressuretype, on the working cylinders or other tedious methods described below.The desideratum of- -the present inventionis: a

First, to accuratelymeasurethe amount of fuel being delivered toany oralltworking "cylinde'rswhile the engine is running thereby determiningthenet amount. of fuel the cylinder (or c linder's)is'receivi ng. a

Seconc to obtain th I boveaccurate measurement without recourse to theinconvenience of havingto measure in a graduated vessel the amount offuel delivered in a certain time. i y Third, to' have" the indicatorrecord curves of such type that all those for one engine,i. e. six for asixlcylin'der. engine, eight for an eight cylinder engine etc. can beput on the same indicator card 7 a. a

Fourth, tohave the recordcurvcs of such type that two orwmore pumpcyclesmay be superimposed thereby reducing any personal crrorpresent inmeasuring the indicator recordcurves. 5 a

Fifth, to provide an refiicient instrument,

for making the above specified records, which is: rugged, is of simpleconstruction, is comparatively inexpensive to manufacture, and whichwill require the" minimum of workto keep same in good working condition.

Sixth,to provides. simplejinstrument which will not require areducingmotion for actuating the indicator drumgand in fact one whereithe drummotion bears no-relation to the fuel pump a piston; motion.

a important objections: 1

..1926. Serial No. "124,065."

measurement of the fuel delivere irrespec- PATIENT 0mm;

7 Seventh, provide an absolutel accurate Vti-ve of the condition of thefuel "pump splunger, valves or plunger packing or of the pressureagainst which the pump works;

heserfunctions cannot be obtained'with de- :v-ices, now irrstandard use.These last mentioned devices are open to a} number "of objections',.- forexample; a I: ,=F1rst {the"connnon method of opening-a ,pypa stalvemulespray valve and measur 1; 1 mia graduated vessel the amount offuel "dcivered' in a given length'of time is extremely inaccurate because thepump is then not working against I the normal working pressure;'there 1sdanger of spilling fuel in that it cantbe made more accurate badjustingthe lifting pressure of the relie valve to correspond to thepressure against which the fuel pump normally works. It adds anothervery objectionable feature, however, in that t it is necessary to stopthe engine to install the relief valve unless one is used and-kepthandling; due to the meniscus formed at the tween the pump and the sprayvalve. Again, a

in air injection engines where-the delivery pressure in the pump variesdue'tothe spray air pressurevarying, it is difiicult to adjust therelief valve tofunction at the various pressures as it musteach time betested in a a system, having a pressure gauge. Pressure gauges are notordinarily installed on fuel lines. a V

Third, the method of taking indicator cards to determine the amount offuel being deopen to several volume indicator cards, is

livered to the working cylinder, i. e. pressurea) -Due to the delicatenature of the pressure indicator it cannot be kept permanently attachedto the working cylinder. It therefore must be set up on thecylinder eachtime a card is to be taken, This means that the permanently installed ineach fuel linebetwo causes.

reducing motion drive for'the ressureindif cator drum has .to beinstalle where, as is often the case, the reducing motion is not 1ncases I wherea separate indicator is used for each working 'cylmden Isensitiveto eaverage pressure 1ndic ator is very the instrument to beinaccurate. i

r (c) Manyother errors are existant in pressure indicators. These are:rdisproportionate motion reduction "causing errors in the area recordedon the indicator card ;'-errors due to lost motlon mthereducmg mot onoints or drive; errors *dueato' variation in the timing ofreducing-motion cams .where same are i used;-in fact, when there is anyerror; in the reducing motion, an error-in the pressureindicator cardfollows; V

;(d) "The. personal'error incident to measurlng pressure mdlcator cardmean-effective rtant. This error 1s due to pressures is im irst, theerror in usingthe planimeter while running theneedle around followingthe; outline of the card. Second, measuring. the distance between thethus found by the planimeter; This total personal error is relativelylarger-at low mean efl'ective pressures-than-at high mean effectivepressures; I p

(e) To determine the mean efl'ective pres- .surefrom a-pressureindicator cardrequires .the use of a planimeter oraveragmgdnstrumentorthe use of .ordmates.

The latter method is particularly laborious. (f):'Finally, indicatorcard mean effective pressures are not an accurate measure of ther'amountof fuel being delivered to the working cylinder. Many other things: suchasleaky "valves;',leak1ngpiston rings, improper atomizatlon of fuel;mproper (118- I .tribution of fuel Where more than one spray valvelisused; ineiiicient scavenging of the.

cylinder; reduction of amount of air reaching a cylinder due toobstruction of the inlet; or to reduction of amount of air passingthrough the spray valve etc. can reduce the mean effective pressurematerially; The fact that one cylinderdoes' have a highermean-efi'ective pressure thananother does not indicate thatuthe unequalpressures are entirely proportional to the fuel beingdelivered to thetwo cylindersinvolved. a

A further objection to the use of. pressure.

. indicatorsi is the fact that they wear fast in.

use and have very'delicate parts which. are difficult to obtainandarevery expensive;

sting, i. e. the-high heat from the Dieselfgngine-cylinder causesdistortion in a machine shop with ordinary tools. of the pressureindicator parts which causes points Figures 7 and 8.

It is therefore afurther object of the" present-invention to provide a:practicable and simple but accurate means for measuring the amount offuel being delivered to the various working cylinders withoutencountering the go 1 use; requiring no specialj attention to cleanmg asis required with thepressure-indicat'or and which can be manufactured orrepaired Itfis to be observed that while the description ofthe-application of this invention'to Diesel engineswill dealparticularly with Diesel engines of air injection type the invention isequally applicable to engines of .85"

mechanical injection or the so-called solid injection orairlessinjection type. In the; accompanying drawings wherein similarparts are denoted by corresponding reference characters Figure 1 is asection through a fuel pump unit of conventional type with a sideelevation of the volume indi-' cator added as a part of the pump.

Figure 2 is a section of thevolume indica- V tor at AA'of Figure 1. I i1 5 Figure 3 is a front elevation of a conventional pump with the volumeindicator installedas a part of the pump. j V

V Figure 4 is a longitudinal section through the center of'the volumeindicator and a coincident plane in the pump.

Figure 5 is a longitudinal section through thecenter of the volumeindicator ina plane at right angles to the section plane shown in.

Figure 4. a

Figure 6 1s a plan VIEW of the volume indicator showing two adjacentfuel pump units.

Figures 7 and 8 show two-longitudinal scc- 1'10 tions, 90 degrees fromeach other, of a volume indicator of one piece body construction. v

Figure 9 is a planview'of Figures 7 and 8.-

Figure 10 is an elevation view of a part of Figures llland 12 aresections of two types of manifolds to be'used when the. volume indicatoris not. to be attached directly to the, fuel pump.- q i j Figure13' isadescriptive volume indica 120 torcard which shows a graph for highpower and another for low power. i

F igure14 is acycle diagram of the conven tional 'fuel measuring pumpusing a conoutput to the spray valve. 7 Figure 15 is an indicator cardobtaine from an ordinary." pressure type indicator Evhcn used on" aDiesel engine workingcylim trolled suction valve for regulating thepumpnzs- Figure 16.is avol unie indicator card showmg record graph for,allsi x* pump cylinders l showing the jpjin llfl passingjjfthrough theon the same card.

Figure 17' isa-volume indicator card which, shows various eculiaritiesof record graph ,Lform which'wifi' faults.

obtain from various pump Figure 18 is'a 'planview of lever,"]36, of-

F gu 2.

bottom. I, t Figure 20 is aview oftliepinfll o. Figure 21 is a view 'ofthefscrew.

Figure 22 is a view ofthe pin retention spring. m m

Figure 23is view oi-the lever, 36,}withithe point-of pin 110 flush withbottom of lever.

In the following discussion the conventional fuel measuring pump using acontrolled suction valve for regulatingth'e amount of fuel delivered tothe spray-valves will be used. It [is q uiteevide'ntthat the volumeindicator herem described, and which is thepresent invention, isapplicablejto any pump which measures and delivers predetermined?amounts to the working cylinder for each en'- ginecycle. I 7 V vReferring now tothedrawingsin detail Passover typefso that whenitisclose does not prevent fuel from passing by ,throughpassage 9.Passage 9fis communb; 'cated withfpassage 12jby valve? 13. Passage andmore particularly to Figurefl wherein.

is shown the volume indicator attached to the fuel measuring pump,.1 isthe fuel pumpsuction, 2 the fuel pump suction valve, 3the suction valvespring, tthe pump lunger and 5 and 6 discharge valves, with and 8 thedischarge valve springs. Now in the con ventional pump the passage 9would be terminatedwith a threaded connection to which the fuel lineleading to the spray vatlvedin tlhe e/attac e n working cylinder jwouldthis invention the passage 9 is communicated with passage 10 by a valve11 which is of the 1t 12: terminates in the threaded connection 14 towhich the fuel line leading to the spray valve o'nithe working'cylinderiscOnn fected.

l ume indicator "In Figures land 5 the passage 1.0 of Figure 1 isindicated by the same number and 'in Figure at the valve'll is the valve11 shown in Figure 1. In fact in allfig'ures, similar parts bear sm larreference numbers.

QConti nuing with Figures land 5i the voloper willjbe described. Inthese figures 1o isthe lower partof the volume indicator body and '16theupper part of the body. T hese two parts' of thebody are held togetherby long capscrews l7 which pass down throughthe columns 18. The up perpart of the bodyfhasfinits center acyhn- Yder 19. fitted with a threadedconnection 20 at its toplq -flhe lowerpart of thebody' has a cylinder21, concentrically arranged n reference to the uppercylinder, The, uppercourse possible and less expensive to i make'lthe two plungers in onepiece. Figure 19 1s a side elevation oflever36,

' The lower part of the body hasan extencylinder is slightly larger thanthe lower 03 1- f inder' as shown and as will be described later.

valveis held on its seat, 26, by a spring, 27,

which rests on a washer, 28, which'in turn is held in position on thevalve by pin, 29. The upper end of the spring rests against a cam lever,30, which in turn rests against the flange of theupper part of the body,16. This cam is soarrangedthat when the lever is in position, 31, Figure6, its upper face rests against the flange of the upper bod When it isin position, 32, of same figure iowever, the cam surface,33,' actsagainst a similar but opposed surface in thebody flange and causes thecam to be driven downward from the body flange thereby compressing thespring, 27, more than when the lever is in position,31. Relief valveoutlet cpnnection 46 is'connected to the lower cylinder 21 by rt 4' 7.,7

The lower art of the body as the outside of the cylin er, 21, turnedconcentric to the cylinder bore to receive the indicator drum,

34. The drum, 34, has at its lower end a ffiange, 35, on which is cutratchet teeth. Into these teethwork a ratchet lever and pawl shown. inFigure 4, andFigure 2, parts, 36, and 37, respectively. The pawl, 37, istlul crumed in lever 36 on pin 38 an'dis heldextended intothe ratchetteeth on the, drum by spring 39. The lever, 36, is fulcrur'ned on pin,

.40; and is limited inits travel by stop pins. 41,

44, and the lever36 is a spring, 45, which allows any mot on n excess ofthe lever motion to be absorbedby thespring, 4 5. This jari rangenientallows allnostany motion to be used to operate theratchet as willbediscussed further, later. i V

The upper plunger, 23, has attached to'it, by screw, 48, the pencilholder, a9. It also carries a stud, 50. which slides in a slot, 51,which slot is cut in'an extension, 52, of the lower cylinder. Thisextension is shown more clearly inFigure 2. a

Theindicator card is held on the drum, 34,- in the conventional mannerby a clip not shown in any of the figures.

Both the upper andlower cylinders have a counter-bore beginning atpoints, 53, and, 54, respectively. The counter-bore in the lower Icylinder is needed to permit clearing the'low .er cylinder of air shouldany air be passed through from the fuel pump. To this end a no I 'passage, 55, terminating in a threadedconnection, 56, is provided. Asmall pet cock of conventional tyfpe may be used in this threaded.

connection or permitting any accumulated air or gas to escape. I Toreduce the height of the volume indi cator the fuel pump block, .57, canbe bored to form part of the counter-borel -of the lower.

cylinder as] shown at'58 of Fig u'r'e's" 1 and -5. This counter-bore isconnected with passage A description of the function ofthe volumefindicator will now be given: but before startin the description itisdesirable to state speci cally what thedesired conditions to be met ari i As was stated above, it is essential that l measurement of the fuelpump discharge delivering normally to the spray valve. This should bemade against thejactual pressure against which the uel pump works whenit is 1 actual discharge pressure is composed of two "valve action ofthe fuel check valves at the '30 spray valve combined with the backpressure leading to thespray valve.

parts .First, the back'pressure due to sprayair,

closed type spray V valves, and which is equal to the spray airpressure; 1

which is always existant in Second,1the back pressure due to'thereliefdue to the resistance to fluid flow in the line Now the spray a1rpressure varies with different load and speed conditions in the en-.gine; but the back pressuredue to check valve and line resistance actionmay be considered practically'constant for any one type of design. Theline resistance will vary'slightly with fluid flow velocity; but thisvariation may generallybei considered as negligible.

. Hence for practical purposes the spray air may be considered as theonly back pressure variable to be considered. Thevalue' of the backpressure factor due tochec'kjvalve action pressure of spray air pressureplus 250 lbs. for

the particular design above considered; In

This may be accomplished as still be de-,[

case the check and line back pressure is diifer ent from 250 lbs. persquare inch and We call 7 this total check and line back pressure X,then 55 in'gcncral the volume indicator should work aga nst spray a1rpressure plus X pressure.

scribed.

sidered non-compressible withinthe pressure ranges which exist in fuelpumps and lines lead ng to spray valves,1n a1r 1n ect1on en-.

, gines. Also assuming uniform air entrainment the fuel oil may beconsidered uniform ly compressible over'higher pressurerang'es it willhave made a straight vertical line on such as exist in airless injectionengine fuel distribution systems.

1 Referrin 13, closed the fuel stops going to the spray valve and flowsthrough passages 9, 59jand "of the piston will be asregular as the flowof the fuel to the under side of same.

To the threaded connection 20, of cylinder, 19, a branch of the sprayair line is connected.

Thus tl1e cylinder'19 has spray. air pressure.

, now to Figures 1, land 5, it is, seen that w en valve, 11, is openedand valve,

in it when spray air is on the spray air line.

p, If plungers 22, 23 were of equal 'size, i. 'e.

of equal-diametenthen the pressure on the oil in cylinder, 21, wouldequal the'pressure of the spray airas the plungers are free to- Imoveto, balance the-pressures aboveand be I But it was shown above 7 that itis desirable to work against'spray, air

low the plungers;

pressure plus the back pressure from check valves and fuel lineresistance. To obtain this the upper plunger, 23, is made slightlylarger in diameter than the lower plunger, 22. This increases the totalpressure above and below theplungersj butas the area of the lowerplunger is notincreased, the unit lower "premure issincreased. Byproperly proportioning'the areas ofthe two plungers the pressure of theoil .underthe plungers may be raised any desired amount above that ofthe spray air. f

Assume that the oil is cylinder as described above and that the plunger.22, is equalin diameter to the fuel pump plunger, 4;, Figure 1. When thefuelpump plunger starts delivering to. the lower indicator cylinder. 58,the plunger, 22, will travelupWarda-gainst the spray air pressure adistance equal to the fuel pump plunger effective delivery travel. Asthe upper plunger is preventedfrom turning by guide pin, 59. sliding inslot,51, the indicatorpencil, 49,'will make a straight vertical markon-the indicator cardof' length equal to the effective travel of thefuel pump, plunger, less any leakage in Assuming no leakage, and aneffective pump plunger travel of onehalf inch, the pencil mark would beone half inch in length. Referring now to Figure 13 let the limits ofthis markbe points 61 and 62. 7 Point, 62, repdirected to the lowervalves or packing thatocciirs.

resents the end of the pump discharge stroke;

and, as the discharge valves are assumed tight,

7 u p -there will be no reversed fluid flow from below For practicalpurposes fuel oil maybe conthe indicator piston. Hence, the pencil willstandstill at point, 62, untilthefnext effective-stroke commences.During the next stroke it will move'up to point, 63, and during 7succeeding strokes to points, 64 and'65. Thus when the pincil reachesthe top of the card,

left no record of the discharge stroke is effective.

the card from bottom to top, but it willhave pump. delivery strokes. Toestablish arecord of the beginning and end of pump delivery strokes itis necessary to'move the indicator card drum, '34, Figure 4, slightl,between pump strokes. ThIS is accomplis ed by the ratchet mechanismparts35, 36, 37 38, 39, 40, 41, 42 and 43 of Figures 2 and 4.

It should be noted here that it makes no difference what time during thepump cycle the indicator drum is moved b the ratchet provided that it isnot move 1 during the effective stroke. 7 v r Refer now to Fi ure 14.This shows the conventional cycle (fiagr m .forthe fuel measuring pumpwhere only thelast half of the Thus, it is apparent that the effectivetravel for full power corresponds to 90 of um crank travel. Asit. wasstated above t at t e volume indicator. drum should not be moved duringthe efiectivetravel; and as this effective travel is a maximum of '90degrees of pump crank travel, it follows that the indicator drum can bemoved by the ratchet at any time during 270 degrees of pump cranktravel. Further, as was set forth above, the ratchet lever may be drivenfrom any moving part of the engine which moves through the same numberof cycles per minute as the fuel pump.

Therefore it is evidentthat great flexibility of ratchetdrive' isafiorded and as set fort above,

needed.

Referring again to Figure 13 and assuming the fuel tobedirected to theunder side of theindicator plunger, 22, of Figures, and assuming theratchet for moving the indicator drun'i to be in action and furtherassuming the indicator plunger to be at the bottom of its stroke {whenthe fuel ipump plunger, 4,

otFigure 1, starts on its e ective discharge stroke, 'the indicatorpencil moves upward from point, 61, and as before stops at point 62.Between thisltinie and the time the plunger commences ts next effectivestroke,

the ratchet moves the drum so that the pencil moves to point 66. Theratchet is operated by string44 that is attached to any suitable movingpart of the engme, such asthe crosshead. or the like. The movement thusimparted the ratchet, engages with the ratchet. teeth on the drum, thelatter is revolved sufliciently to allow the pencil to begin itsn'extupward stroke in a line different from the preceding one. Then on thenext effective pump stroke the pencil movesupward to point,67. Be

tween eftectivestrokes the indicator drum is again moved by theratchetso that the pen oil travels from 67 to 68. In like manner thecurve is continued upward through points beginning or ending of noproportionalreducing drive motion such asis requlred for pressureindicators is Obviously, the first an to the ratchet causes it to turnabout its pivot, and as pawl 37, that ismounted on a 69, 70, 71, 72 andto point 7 5. We then have,

as a record of the fuel pump performance the graph through points 61,62, 66, 67, 68, 69, 70,

1, 2 and 75.

' Now as the length of the vertical lines represent, directly, efiectivefuel pump plunger travel; to determine the effective plunger travel fromthe card it is only necessary to measure the lengthof the verticallines, i. e.,

one third of what it would be for only one step.

It is important to note that, though the record graph extends from thelower extreme of the card to the upper extreme, there is no assurancethat the point, 61, as shown marks the beginning of a pump stroke.Likewise, there is-no assurance that oint, 75, repj resents the end of apump stro e. But lines passing through points 62 and 66 and 71 and 72 dorepresent the ends of pump strokes;

therefore, they maybe used with certaint for measuring the plun ereffective trave last steps in the graph should be used. a U .Referringnow to Fi ure 15, let it be assumed that the mean e ective pressure isto be determined by use of a planimeter. The usual and simplest methodis to start at point 76, with-planimeter wheel scale at zero and run theplanimeter needle around the card back to point 76. Then the planimeterneedle is moved up a vertical line until the planimeterwheel scale againregisters zero.

This position is represented here by point 77. The distance betweenpoints 76 and 77 is then measured to determine the mean effectivepressure. Now it is obvious that there are two personal errors involvedin this measurement First, that due to running the planimeter needlearound the indicator card;

Secondthat due to measuring the distance between points 7 6 and 77.

Tliesetwoerrors, plainly, may be cumula- It is desirable to reduce thetive or differential; but the accumulative effect must be considered.The first error is fairly large at times and requires greater deftnesson the part of the operator than does the latter operation. I b

b )nsidering now the last operation, assume that the line, 76. to 77, ofFigure. 15 is one half inch long, and that an error of one one hundredthinch is made in measuring the line. Then the percentage of errojrfisequal to =.02, .o2 1'00=2 per cent;

-Again, assume that the line 76,to, 77, is

only oneeigh'th inch long and the error in measuring is again one onehundredth inch.'

Here the percentage 0f error is .08,

.osx 100=8 percent. 7 The same, effect. 0btains from the first error. rFrom these considerations it is plain that ,the relative effect of thepersonal. error in measuring pressure indicator cards varies inverselyas the mean effective pressure of the cards considered, i. e., theaccuracy is greatl est where the mean effective pressure is greatest andv the accuracy least where the mean effective smoothness of operation atlow powers depends on fineness of balance of mean effective pressuresand as the personal measuring accuracy'variation is unfavorable to lowmean efl'ective pressures it follows that the pressure indicator card isat a disadvantageat low engine powers. 7 i Consider now thepossibilitiesof the-volume indicatorcard. Assume that the graph of also,that each of the vertical steps 66 to 67 ,"68.

tance,

74, isequal to one and one half inches.

7 Assume further, that thesame personal error is made lnmeasurmg thisline as was assumed v made'in measuring line, 76 to 77,'of Figure 40volume indicator card 15, viz., one onehundredth inch. -Then thepercentageof this error will be: .66 per cent or one third of that whichobtained Figure 15 for full power. Compared with the error whichobtainedfrom the pressure indicator card where only one eighth-inch length wasassumed for line, ure, 15, i. e. low power condition, We find that thepersonal errorlam'ounts to only one twelfthgof that found in i of thepressure indicator card. V

N ow in the case of low engine powers the v will look like graph, 78, to79, of Figure 13. The vertical steps in this graph are assumedone eighthinch long. This is the same as the low length assumedin case of the lowmean effective pressure in the pressure indicatorcardinmakingcomparisonsabove. As before, the first andlast steps from.

the indicator card upper and low margin will be used. But in this caseweare measuring 16 pump cycles superimposed instead ofj3 pump Now as thecycles superimposed as before.

pressure is the minimum. As

thing would burst.

manipulation isimpracticali Then the dis Then the total pressureis1500lbs. m-measuring the pressure indicator card of 7 7 to 7.7 f g the.cam

be 1750'lbs. persquare inc h 9 5 connected by a line'to the suction lineof the vertical steps ofthis graph wereassumed one eighth inchinlength,the distance 801s equal to two inches. Againassuming a personalerror in measuring of one one hundredth inch 1 we find .5 per cent. Thisis only one sixteenth ofthe percentage of error found great as that ofthe pressure indicator card for full power of the engine and it issixteen times as accurate as the card for low engine power r V VReturning nowto graph 61, 62, 66, 67 68, 69, 70, 71, 2and 75, of Figure13, it is evident that when the indicator pencil is at point, 7 5, theindicator plunger is at the top of its stroke, theupper end ofplunger'23 of Figure 5being against the plug 60.: Now if there were nooutlet provided for the fuel,'sometherefore for the excess oil. 7 V j Ofcourse, if the valve 13 ofFigure 1 could be opened at theinstant thevolume indicator pencil reaches point of Figure 13, no excess pressurewould be developed. But unless valve 11 of same time the indicator mightV discharge a largeslug of fuel into the fuel pressure indicator Outletprovision is made" same figure were closed atjthe line. i This T Toobviate these difliculties the relief valve V 25 of Figure' 5 is above,the cam lever, 30, has two positions which provides two different valuesfor the compression of the spring 27.

Now suppose the maximum spray air presprovided. As described.

sure to be used on anengin'e is 1200 lbs. per

' square inch and that the combined check valve and line drop is" 300lbs. per square inch. Suppose now that it is desired to provide a marginof pressure of 250 lbs. per square inch.

pressurereachesl750 lbs. per square inch.

7 l t Then i the relief valve should be set to lift when the The springshould beso designedthat when Threadedconnection, 46 6f Figure 5 is ofthe volume indicator will rise to 1750 lbs.

per square inch when the relief valve will lift allowing the remainderof the charge and any succeeding j charges to fflow, through threadedconnection 46 back to the pump, sucis in its high compressionz positionj the liftingfpressure'for the'relief valve will by plug '60, thepressure within the fuel pump and within the oil end tion. Thusall oil'goingtothe indicatoris passed back to the suction, thereby providing aclosed c1rcuit,-so no fuel oil is at any timeliberated to maketheoperation unclean or distasteful to the operator. t y

"As the relief valve maintainsla pressure of 1750 lbs. in the indicatorf el oil end, which is greater than the airfpressure above the plungerit is. evident that theindicator .move downward. drivingtefuel oil outto the suction of thepump. Thus relieving the ressure to a. lowerpressure but not reducing it to zero has two distmct'advantagesz '(a)First, it prevents the'indicatorplunger from being driven downyiolentlystriking the-bottom of its cylinderi 1 V l tremely slightcompressibilityof thefuel oil;

. and prevents the admissionof air from any source to the underside ofthe indicator plunger.

cleared, of course, with spring having only'la single compressionradjustmentbut havinga relief lever provided for lifting the valve sli'htly againstthe spring pressure thereby .allbwing the fuel oil tobedriven back to the pump suction." This arrangement lacks the advantagesattributed to. the first mentioned and described one. y

The vent connection. and 56. of Figure 4 could be used to clear theindicator of fuel {011 but should be usedonly to remove any air or gasaccumulated below the lIlCllCfltOl" plunger.

As will be shown, it is necessary to stop the ratchet action at times.Forthis function a stop is provided.

Figure 18 is'lever 36 of Figure 2.. This leverhas a boss 108 throughwhich. is drilled the hole 109. Into hole .109 is fittedpinfllO.

This pinniay be pushed down so as to have its point flush with the lowerside of the lever as shown in Figure 23; or it may be pushed down so asto have its point a: short distance 1 through the lever as shown inFigure 19; The

- pin-is heldin place by aspringclip, 113, of

, Figure 22 having a sl1arpedge,j114,'which bears'in grooves flfi and3116 of pin 110, of

- Figure 20. A hole isprovided injthefbody piece 16 of Figure i underthe lever;36 into which the point of pin1110 (Figure 19). passes -'whenthe lever 36 is atrest against pin 41 of Figure 2. Whenthe pin is downso that it is in the hole in the body piece 16 the spring clip sharpedge 114 stands in groove that its point is flush withthe lower side Iof the lever 36 the spring clip sharp edge 114 up n I lowing (b) Second,it lessens the efiect oflthe exclip 113 is held in place on lever 36 byscrew 117. i y 1 When it is'dcsired t6 stop the ratchet it is necessaryonly to push down on. the pm 110. When thisis done the pin engages thehole in the body 16 and stops the ratchctac- 'tion compelling the spring45 to absorb all the motion imparted by the driver but not re quiringanything to be disconnected, To put the ratchet back into action it isnecessary merely to pull the pin-upward so as to cause the clip to snapinto groove 116 of pin 110.

It will be noticed thatithe usual stop ratchet pawl for preventing thedrum from oscillating with the ratchet lever 36hasbeen omitted. For mostdesigns this ratchet stop pawl will be found unnecessary, because thereis suflicient friction betwcenthc drum and the cylinder to prevent thedrunifrom folthe retiring stroke of the ratchet. If

neede a stop pawl may be provided as shown at118 of Figure 2. Thispawl118 fulcrums on pin 121and is held against the ratchet travel.

Assume that graph 89 to 90 is recorded by the indicator as was curve 61,62, 66, 67, 69, 70, 71, 72 and 75, described above. When the pencilreaches point 90 the cam lever '30 of Figure 5 is thrown to its lowcompression position and the indicatoraplunger 23 -moves downward, thepencil m ing line 91 to 92.

Here it is assumed the ratchet described above'forjmoving the indicatordrum is stopped from acting b the stop above de-" scribed. It is obviousy desirable to allow.

the ratchet to move the drum so as to cause the pencil to move frompoint 90 to point 91 {as this separates the curves. When the indicatorplunger reaches the bottom of its stroke causing the pencil to stop atpoint 92, it is necessary to open valve 13 and close valve 11 teeth onthe drum bycompressedspring 120 t a which in turn rests against pin 119.The indicator fuel oil cylinder can. be

of Figure 1. Then a valve similar to 11 leading to another cylinder isopened and one similar to 13 is closed and the ratchet thrown a backinto action. 7 When this, is done the.

gr ph 92 to93is recorded for working cylin- Vder number two. In likemannergraphs are obtained {for all theworking cylinders as shown a tThese fuel delivery records for all work: ingfc-ylinders on oneindicatorcard provide an easy comparisonbetween the various units a andleave no opportunity for getting records I .mixed as occurs" where aseparate pressure 115 of Figure 20 but when thepinis up so card isrequired foreach working cylinder.

The record graphs described above are those which would obtain with novalve leaks or erratic action of the suction or discharge Fward travelto it would work.

valves. The volume indicator will show these above mentioned and other.faults of. pump actiom f e Referring to Figure 17, which re resents anindicator card similar to that 0 Figure 16, graphs 96 to 97 and 98 to99; show the i type iof graph whichrrwould obtain-from a pump havingleaky discharge valves. In this case-the indicator'pencil would make itsup- ;points 100 but between circles ownward to pointsIOl. The characterofthe curve between these points would depend on the degree of leakthrough the valves, and on the time in the ineffective part of the pumpcycle at which the ratchet moves the indicator drum. Diagrams 102,

103 andf104 show three cases that could oc- 1 V cur. In F any casehowever the vertical distance between points 100 and .101 ofgraphs 96 to97 and 98 to 99 show very definitely the amountofleak which is occuringin the dis by the fuel-pump suction valve adj ustment.

If all other pump characteristics are normal,

. equal adjustments of the suction valves will cause equalized deliveryfrom all 7 pumps.

However, leaking pump plunger packing'and leaking suction valves and anyother leaks from pump plungerchamber back' to the pump suction ortotheatmospherewillcause the vertical step inlthecard to be shortenedwithfa normal suction valve setting As plunger packing leaks are visibleand assuction valve adjustment can be readily inspected 'it is e asyito'determineifthere is a leak desirable tostop the engine'forrepairs, the

back to the pump suction through a suction V valve leak. If volumelndicator cards'are taken withlthe engine running andany of the abovefaults are found to exist, but it is unsuction valve tappet adjustmentcan be changed while the engine 1s running. After the adj ustment ismadeanother volume indicatorcard istakeniocheck the adjustment low. p pThe advantages of this one piece bodyftype The type" of volume indicatorwhich has just been described is of two piece body construction.- Thistype has the advantageof havingthe drum and pencil carrier wellenclosed. This i's an important consideration because the instrument isto be kept [permanently installed on the engine; audit-is there- 7.{foresubject to incidental knocks as are other parts of the engine. .Adisadvantage of this type is that it is more difficult to put anindicator card on the drum, Another disadvantage is, that as therearetwo pieces inthe body, the cost of manufacture would be i higher than ifone piece body" construction were used;

7 "Figures 7, 8, 9 and 10 show a. volume indi- 1 cater of one ieoeibody'construction. This," 7 is much simp er in construction, Itsfunctiom'ng is identicalto that of the two piece construction, the basicdifference being that the drum 34, and the pencil carrier, 49, .are'

-outside of the instrument;and that/the one piece body, 118," takes and16 of Figure 4. i j The detail differences are V (a) Vent connection,119, takesthe place of ventconnection, 5 6, of Figure 4.

(b) Pencil carrier, 49, is'carried by an extension stud, 120,-insteadofthe screw, 48, of

Figure 5.- This extension stud, 120, also takes theplaceof the guidepin, 50, of Figure 4.

:place of parts, 15,

It slides in the guide, 121, which 'isaslot in 7 the side of theindicator body. (a). The pencil. carrier being loosely attached to theextension stud, 120, requires a steady bearing at its top. This isprovided i by a groove in the body casting at, 122, in

'. which the pencil carrier, 49, is fitted." The H pencil-"carrier isheld into this'i cllp, 123,; and screw, 124.

groove by (d) The ratchet lever, -125,forms a ring which runs around thebodyjof the indicator as shown in Figures 7,8, 9 and 10,by thc number,125.1LThe oscillating motionof this "lever'jring is prevented fromaffecting the drum 34 by aring, 126, which is fixed in its body casting,118.

'(e) The lever ring, 125, is given its backf ward motion by spring, 128.011 one end it is attached to pin, 129, which in turn screws into leverring, 125. The s'prings other endis attached to pin, 130, which in turnpasses through a slot, 131, in the lever ring. Its

Qfunction is the same as thatof spring, 43, of

position by screw, 127, which screws into the (f) Ratchet pawl, 132,takesthe place of drum, 34, by

of indicatorare that it can be manufactured cheaply;

'sible;fand it is much more'comp'act. In general the one piece type isbetter for portable use or where it is to be used in a manifoldinstalledin the fuel lines." The "two piece type is better where thereis plenty the indicator drum is very acces r 'Itis not always possibleto istall the vol 7 ume indicator on the fuel m suring pump due to spacelimitation. In this case, and also in the case wherean engine is in usewithout a volume indicator, it is advisable to install a manifoldthrough which all the fuel oil leads run on their way to the sprayvalves.

Figure 11 shows one arrangement for the manifold. In this, fuel isreceived from a line from the fuel pump into connection 136, and 137.The oil passes from 137, into .passage, 9, which is identical topassage, 9, of Figure 1. The oil passage through the manifold from thispoint is identical to its passage from passage, 9, of Figure 1, to thespray valve. The corresponding parts have been given similar numbers tothose used in Figurev 1. 1

Figure 12 shows a different t pe of manifold. It functions as follows:he fuel from the fuel pump enters passage 138, through connections, 139.Valve, 140, is normal y kept open and valve, 141, is normally keptclosed. The fuel then passes through passage, 142, to passage, 143, fromwhich it passes to the spray valve. If, however, it is desired to directthe oil to the volume indicator, valve, 141, is opened and valve, 140,closed. The oil then passes through passage, 144, thence past valve,141, to passage, 145. The volume indicator is attached to threadedconnection 146. This manifold arrangement has the advantage of havingboth valves readily accessible and offsetting the fuel lines the minimumon the way to the spray valves.

Passage, 147, runs through the manifold to connect all units of themanifold as does pas-.

sage, 10, of Figure 1.

Summarily, the volume indicator has many practical advantages:

(a) Cleaning is not a vitally important requirement for successfuloperation as is the case with the pressure indicator. It needs no morecleaning than other small parts of the engine. l

(b) It is rugged in construction and has no parts which require veryfine precision grinding.- Every part can be made in an ordinary machineshope. There are no finely calibrated springs to be made and frequentlytested.

(0) No planimeter with its incidental errors or laborious process, suchas the layin out of ordinates on a pressure indicator card to determinethe-mean effective pressures, is required to read the record graphs ofthe volume indicator.

((2) The volume indicator provides an easy, practicable and sure meansof determining the qualit of fuel measuring pump performance wit outstopping the engine.

(e) It exposes no oil to the engine room-- ,the entire circuitbeingclosed.

(f) It puts the record graphs for the entire engine on one card.

(g) It provides a record graph which becylinders hasbeen balanced up byuse of the volume indicator an intelligent analysis of other enginefaults can be made. With the usual method of operation the exact amountof fuel being used cannot be determined. Pressure indicator cards aretaken and if mean effective pressures are unbalanced the fuel quantityis increased to the cylinder having a low mean effective pressure. Thisrocedure may or may not be correct. he volume indicator provides apracticable and accurate means of determining this question ofprocedure.

(m) The volume indicator is a safety instrument. In the case where a lowmean effective pressure is found to obtain in a working cylinder, andwhere this is actually due to poor atomization or other factor causingslow burning, but which low pressure is thought due to low fuel supply,the fuel pump is changed so as to deliver more fuel. This results inproportionally greater afterburning with correspondingly moredetrimental effects on exhaust valves and cages or exhaust ports in twocycle engines, besides a smoky exhaust. The volume indicator provides arepoor.

It is plain therefore that the exhaust temperature is not a measure ofamount of fuel being delivered to a cylinder. This is one reason why theexhaust pyrometer is not an absolute safeguard against uneven loading ofthe working cylinders.

What I claim is 1. A volume indicator for gas engines including a fuelpump, a fuel line to spray valve, an indicating means consisting of adrum, a record card carried thereby, a pencil operable upon the card,and means for actuating the pencil. said means comprising a plungercontrolled by the difference between I the pressure of oil beingdelivered andthe pressure of spray air being used in the engine.

'2. A fuel volume indicator for gas engines including a fuel pump, afuel line to spray valve, anoil cylinder, an air cylinder, a recordingmeans, a pencil operable thereon, and means for actuating the pencil,said means comprising a plunger operable within the said cylinders andcontrolled by the difference of pressure therein.

.3. A fuel volume indicator for 'gas engines including a fuel pump, afuel line to spray valve, an oil cylinder, an air cylinder, saidcylinders having diflerent areas, a recording means, a pencil operablethereon, and means for actuating the pencil, said means comprising aplunger operable in the cylinders and having diameters corresponding tothose of the cylinders, said plunger being controlled by the differencein pressure in the cylinders.

4. A fuel volume indicator for gas engines including a fuel pump, anindicating mechanism operated by a difi'erence in pressure exerted thereagainst b the fuel from the pump, a manifo d, a fue line from the pum tothe manifold, fold to spray valve, and a fuel line from the manifold tothe indicating mechanism, said manifold admitting fuel to the indicatingmechanism line While temporarily excluding fuel from the spray valveline.

5. A fuel volume indicator for gas engines including a fuel pump, anindicating mecl1anism operated by a difference in pressure exerted thereagainst by the fuel from the pump, a manifold having a fuel inlet andfuel outlets to the indicating mechanism and spray valve, a valvecontrolling the inlet, a valve controlling the outlet to the indicatingmechanism, and a valve controlling the outlet to spray valve.

Signed at Washington, District of Columbia, this 14th day of June, 1926.

JOHN E. CANOOSE.

a fuel line from the manl

